The color stability of rose-scented tea is affected throughout the entire process, from raw material processing to finished product packaging, involving multiple stages such as fresh flower pretreatment, scenting techniques, drying methods, and storage conditions. Its core lies in scientifically controlling process parameters to reduce the degradation and variation of natural pigments, while avoiding color abnormalities caused by human intervention, ultimately achieving a natural, lasting, and stable color for both the tea infusion and dried flowers.
Fresh flower pretreatment is the primary step in achieving color stability. After harvesting, roses need to undergo proper spreading, petal folding, and stem and stamen removal to ensure clean petals for scenting. This process requires strict control of spreading time and environmental temperature and humidity to prevent premature oxidation of pigments due to excessive heat. For example, if the spreading time is too long or the environmental temperature is too high, the anthocyanins in the flowers will decompose more rapidly, resulting in a dull color in the subsequently scented dried flowers. Simultaneously, the thoroughness of stem and stamen removal also affects the color; residual stems may discolor during drying due to high moisture content, thus contaminating the overall color.
The scenting process is a crucial step in determining color stability. During scenting, tea leaves and fresh flowers are mixed in a specific ratio. Through the combined effects of temperature, humidity, and time, the aroma and pigments of the flowers infuse into the tea leaves. If the scenting temperature is too high, the pigments in the flowers will lighten due to thermal degradation, resulting in a whitish color in the dried flowers; if the temperature is too low, the pigments may not dissolve sufficiently, affecting the richness of the tea liquor. Furthermore, controlling the scenting time is also critical. Too short a time will lead to incomplete pigment transfer, while too long a time may cause excessive oxidation, resulting in a darker color. Therefore, precisely controlling the scenting parameters is key to maintaining color stability.
The drying method also significantly impacts color stability. Rose-scented tea is typically dried using low-temperature drying technology to minimize the damage to pigments caused by high temperatures. While high-temperature rapid drying can shorten the production cycle, it leads to significant degradation of pigments such as anthocyanins, causing the dried flowers to turn yellow or brown. Conversely, while low-temperature drying takes longer, it preserves natural pigments to the greatest extent, giving dried flowers a natural purplish-red or dark red hue. Furthermore, ventilation during the drying process also affects color; poor ventilation can lead to localized overheating and pigment variation.
Storage conditions are crucial for long-term color stability. Finished rose scented tea should be stored in a cool, dry, and dark environment to prevent pigment degradation due to light, oxidation, or moisture. High humidity can cause dried flowers to absorb moisture and become damp, resulting in a dull color; excessive light can trigger photo-oxidation, causing pigment fading. Therefore, sealed packaging and light-protected storage are effective means of maintaining color stability.
Illegal processing methods such as sulfur fumigation severely damage color stability. Some merchants use sulfur fumigation on roses to achieve a brighter color in the short term. While this may give the flowers a vibrant red color in the short term, sulfur residue damages the waxy coating on the flower surface, accelerates pigment degradation, and produces harmful substances such as sulfur dioxide, posing a health risk. Long-term consumption of sulfur-fumigated rose scented tea not only results in poor color stability but may also cause gastrointestinal discomfort and calcium absorption problems.
The choice of tea base and the scenting ratio also affect color stability. Different tea bases (such as black tea and green tea) and rose petals have different scenting ratios that directly affect the color of the tea liquor. For example, black tea bases may produce an orange-red liquor after scenting, while green tea bases may appear pale yellow or light green. A proper scenting ratio allows the tea liquor color to complement the dried flower color, enhancing the overall aesthetic appeal.
The processing techniques for rose scented tea have a multi-dimensional impact on color stability. From raw material pretreatment to finished product storage, each step requires strict control of process parameters to minimize pigment degradation and variation. Simultaneously, illegal processing methods such as sulfur fumigation must be resolutely resisted to ensure the natural, lasting, and safe color of the rose scented tea.
